耙db：migration中止

Question

我有一个未完成的项目，开发人员没有完成，并且没有留下任何有关安装过程的文档。 我已经将生产目录下载到我的Windows机器上（运行InstantRails 2），我在database.yml中创建了所需的database.yml并尝试运行rake:db:migrate --trace但是收到以下错误信息：

(in D:/projects/broke2)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:migrate
rake aborted!
uninitialized constant Admin
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/dependencies.rb:279:in `load_missing_constant'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/dependencies.rb:468:in `const_missing'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/dependencies.rb:480:in `const_missing'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/inflector.rb:285:in `constantize'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/inflector.rb:284:in `each'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/inflector.rb:284:in `constantize'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activesupport-2.1.1/lib/active_support/core_ext/string/inflections.rb:143:in `constantize'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:481:in `migrations'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/connection_adapters/mysql_adapter.rb:15:in `inject'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:465:in `each'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:465:in `inject'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:465:in `migrations'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:431:in `migrate'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:373:in `up'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/activerecord-2.1.1/lib/active_record/migration.rb:356:in `migrate'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rails-2.1.1/lib/tasks/databases.rake:99
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:617:in `call'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:617:in `execute'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:612:in `each'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:612:in `execute'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:578:in `invoke_with_call_chain'
D:/InstantRails-2.0-win/ruby/lib/ruby/1.8/monitor.rb:242:in `synchronize'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:571:in `invoke_with_call_chain'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:564:in `invoke'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:2019:in `invoke_task'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:1997:in `top_level'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:1997:in `each'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:1997:in `top_level'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:2036:in `standard_exception_handling'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:1991:in `top_level'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:1970:in `run'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:2036:in `standard_exception_handling'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake.rb:1967:in `run'
D:/InstantRails-2.0-win/ruby/lib/ruby/gems/1.8/gems/rake-0.8.3/bin/rake:31
D:/InstantRails-2.0-win/ruby/bin/rake:19:in `load'
D:/InstantRails-2.0-win/ruby/bin/rake:19

我是一名常规的Rails开发人员（这不是我的第一个应用程序），但是我从未见过此错误，而且我不知道从哪里开始调试。

Answer 1

如果在Admin中定义了语法错误，有时Rails会抛出此错误。

尝试查找admin.rb并确保对其进行了解析。

另外，您可能想尝试一次运行一次rake db:migrate VERSION=1 （ rake db:migrate VERSION=1等），以查看这是否有助于您找出导致该错误的迁移，或者只是通过引导应用程序来解决问题。

Answer 2

我怀疑您进行了迁移，该迁移创建了一个表并使用模型添加了一些数据。 在项目的后期，模型被重命名或删除（表可能也一样？）。 由于该模型已不存在，因此迁移无法运行，但是没有人注意到，那时迁移一次只运行了几次迁移，而不是从干净的数据库中进行。

这里的课程...如果您重命名模型或表（或更新其验证和字段），然后检查从头开始在当前生产版本上进行的迁移。

Answer 3

我想说您的问题出在迁移问题的uninitialized constant Admin部分中。 您是否尝试过查找Admin的初始化位置，并包括使用它的位置的路径？ （此外，您正在运行的rake任务的内容是什么？）

Answer 4

它没有指出我有管理常数的位置。 有一种方法可以检查至少我应该看哪里？ 我的模型，我的控制器等？

rake db：migrate VERSION = 1，已经给我一个错误。 就像我告诉你的，我只是想完成另一个人未完成的项目。

如何为每个文件制作迁移文件？

问候，

胜利者

Answer 5

您可以尝试一次全部加载架构，而不是执行每次迁移：

耙db：schema：load

正如RichH所说，架构可能有所变化，未反映在迁移中